*{
    margin: 0px;
    padding: 0px;

}
html,body{
    opacity: 0.9;
    height: 100%;
}
body{
    display: flex;
    flex-direction: column;
}
ul li{
    list-style: none;

}
header{
    height: 50px;
    background-color: yellow;
    /* color: red; */
}
section{
    background-color: red;
    flex: 1;
}
footer{
    height: 100px;
    background-color: black;
}
.desktop{
    display: none;
}
.ipad{
    display: inline-block;
}
.mobile{
    display: none;
}
